Tenney norm: Difference between revisions

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Added: " It is also known as ''log product complexity''."
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If p/q is a positive rational number reduced to its lowest terms, then the [[Benedetti height]] is the integer pq. Often it is more convenient instead to take the logarithm, usually base 2 ([[log2]]), of the [[Benedetti height]], leading to Tenney [[height]]. In either form it is widely used as a [[measure of inharmonicity]] and/or complexity for intervals. It is also known as ''log product complexity''.
If p/q is a positive rational number reduced to its lowest terms, then the [[Benedetti height]] is the integer pq. Often it is more convenient instead to take the logarithm, usually base 2 ([[log2]]), of the [[Benedetti height]], leading to Tenney [[height]]. In either form it is widely used as a [[measure of inharmonicity]] and/or complexity for intervals. It is also known as ''log product complexity''.


The '''Tenney height''' of a [[monzo]] is given by
The '''Tenney height''' of a [[monzo]] b = {{monzo| ''b''<sub>π (2)</sub> ''b''<sub>π (3)</sub> … ''b''<sub>π (''p'')</sub> }} is given by


<pre>|| |e2 e3 ... ep&gt; || = |e2| + log2(3)|e3| + ... + log2(p)|ep| = log2(2^|e2| * 3^|e3| * ... * p^|ep|)</pre>
<math>\lVert W^{-1}b \rVert = \vert b_{\pi (2)} \vert + \log_2 (3) \vert b_{\pi (3)} \vert + \ldots + \log_2 (p) \vert b_{\pi (p)} \vert = \log_2 (2^{|b_{\pi (2)}|} \cdot 3^{|b_{\pi (2)}|} \cdot \ldots \cdot p^{|b_{\pi (p)}|})</math>
 
where W is the Tenney weighter such that, for the prime basis Q = {{val| 2 3 5 … ''p'' }},
 
<math>W = \operatorname {diag} (1/log_2 (Q))</math>


== Examples ==
== Examples ==